SK-1 MIDI DIY or DOA?

[halidex]

I've been searching around for a straight forward MIDI retrofit solution for the SK-1. Low and behold I found it here on this forum pointing me to the Highly Liquid UMR2 and the lovely instructions. As my luck would always have it, looks like I missed out on by a couple of years. Anyone have any suggestions for an alternative?

[Circuitbenders]

There aren't any alternatives anymore as far as i'm aware

[gmeredith]

There is here:

http://midikits.net/products_prices.htm

These are basically the same thing but using arduinos. Lots of options and variants.

[Circuitbenders]

Which did you have in mind?
I can't see anything on that site that would let you add midi to a SK1.

[gmeredith]

Yes it's a bit confusing, I had a closer read.

It appears that these are the equivalent to a the UMR2 MIDI to key matrix board. When John was selling his UMR2 he replaced it with the MIDI CPU, to make it generic for all types of keyboards, rather than just the SK, as I understand. The different variants here are for larger or smaller keyboards - the MIDI to 10 outputs and the MIDI to 62 outputs are what I'm referring to:

http://midikits.net/products/decoder_outputs/decoder_outputs.htm

However, you'll need to connect each +5V logic out to some sort of relay chip array to "press" the note keys on the SK key matrix, unlike Johns boards which sent a scanning pulse on each matrix input to the SK CPU


These boards here seem to be a MIDI OUT board - where you can turn your SK into a MIDI controller keyboard with a MIDI OUT:

http://midikits.net/products/keyboard_encoders/keyboard_encoders.htm

[Circuitbenders]

To be honest that site has always somewhat baffled me. I've never been quite sure what their stuff actually is, and what it does.
Surely in order to use those boards you'd have to wire 32 outputs up to switching devices, and then wire those switches up across every single key on the SK-1 keyboard. I guess its doable, but its a massive amount of wiring.

The MIDECO from Midi Hardware does much the same thing without the arduino http://www.midi-hardware.com/index.php?section=prod_info&product=MIDECO

Its a shame the UMR2 was discontinued as it was a far more elegant solution with a tiny fraction of the wiring involved.

[gmeredith]

It should be able to be done in the same way using switches, I would think, regarding in the way the SK key matrix works. Putting a micro switch on each key would be doubling/tripling/quadrupling up on switches, since groups of keys in the matrix are related/connected. You should be able to do the same thing with switch groups. I think. One day I'll sit down and think about it better 

[Circuitbenders]

The theory is sound i guess. I'm not sure i'd attempt it without my brain dribbling out of my ears though.

A whole lot easier if you can just wire it up, put your UMR2 into learn mode and then play each key in turn so it learns the diode matrix for you.... 

[gmeredith]

Yes I agree. I have 6 keyboards here with various models of HL boards, from the original SK MIDI to the UMR2 to the MIDI widget and MSA boards. I wonder if John would licence the boards to other people to make??

[Jaytee]

Just a heads up, the UMR2 boards went open source and you can now buy clones on eBay or make your own.

[wax+wire]

Any updates on this?  Suggestions on best approach? Arduino vs highly liquid (though those PCBs I've seen for sale aren't populated, which I imagine would make them more costly, and potentially difficult)

[SynthularModulus]

I was looking at the UMR2 boards on Ebay, for about 40 bucks. Tempted to get one and put it in an SK-1. Does anyone know if it comes with good documentation for doing the SK-1 install?